Dripless liquid dispenser

ABSTRACT

A dripless liquid dispenser having an inlet for receiving liquid at dispensing pressure and one or more dispensing ports through which the liquid exits from the dispenser. Each port is provided with an individual pressure-actuated valve which opens to pass liquid to the port when liquid is supplied to the dispenser inlet at normal dispensing pressure and closes to block dripping of the liquid from the port when the supply of liquid to the dispenser is Shut off. The preferred dispensing port shutoff valve is an elastic valve sleeve surrounding the communicating passage between the port and dispenser inlet and having an exit end located immediately adjacent the port which normally assumes a constricted configuration wherein the sleeve blocks liquid flow to the port.

United States Patent 2,605,026 7/1952 Wagner. 2,670,884 3/1954 SwartzABSTRACT: A dripless liquid dispenser having an inlet for receivingliquid at dispensing pressure and one or more dispensing ports throughwhich the liquid exits from the dispenser. Each port is provided with anindividual pressureactuated valve which opens to pass liquid to the portwhen liquid is supplied to the dispenser inlet at normal dispensingpressure and closes to block dripping of the liquid from the port whenthe supply of liquid to the dispenser is Shut off. The preferreddispensing port shutoff valve is an elastic valve sleeve surrounding thecommunicating passage between the port and dispenser inlet and having anexit end located immediately adjacent the port which normally assumes aconstricted configuration wherein the sleeve blocks liquid flow to theport.

DRIPLESS LIQUID DISPENSER BACKGROUND OF THE INVENTION 1. Field of theInvention This invention relates generally to the field of liquiddispensing and more particularly to a novel dripless liquid dispenser.

2. Prior Art It will become evident as the description proceeds that thepresent liquid dispenser may be used for various purposes. However, theinvention is concerned primarily with and will be disclosed in relationto glue applicators for carton forming and sealing machines and thelike.

A typical carton forming and sealing machine operates on cardboardblanks for partially fonned cardboard carton structures which are foldedto final carton configuration as they pass through the machine. Suchcartons commonly have flaps to which glue is applied at one section ofthe machine. These glue-coated flaps are then folded to final positionat a following station of the machine and retained in folded positionuntil the glue sets sufficiently to fonn a permanent bond.

A variety of glue dispensers or applying systems have been devised forsuch carton-forming machines. The present invention is concerned withgluing systems of the type which embody a supply of liquid glue underpressure, one or more glue dispensers or applicators which are disposedto apply glue to the carton surfaces to be bonded, and a solenoid valvefor controlling glue flow through each applicator. In some gluingsystems of this type, a single solenoid valve serves a number of glueapplicators. This'valve arrangement reduces the number of valvesrequired and hence the cost of the gluing system, permits placement ofthe valves in readily accessible locations where they can be easilyserviced, and minimizes the size of the applicators. Hence, the valvearrangement presents the disadvantage that relatively long glue-filledpassages exist between the valve and its glue applicators. When thevalve is closed, the glue within these passages tends to drain throughthe dispensing ports in the glue applicators. Such glue drainage, ofcourse, is undesirable for the reason that it fouls both the machine andthe cartons.

An alternative type of gluing systems which alleviates this drainageproblem to some degree employs solenoid valves which are embodieddirectly within the glue applicators. This arrangement locates the valvefor each applicator in relatively close proximity to the applicatordispensing port and thereby reduces the glue drainage which tends tooccur when the valve is closed. However, the cost of these combinationglue applicator and solenoid valve units is relatively high. Moreover,the glue applicators, and hence their contained valves, are generallysituated in locations which are not readily accessible for servicing.The applicators are also quite bulky in size. Moreover, since a typicalglue applicator of this type has a number of dispensing ports and asingle valve for controlling flow through all of the ports, theapplicator still permits an undesirable amount of glue drainage owing tothe existence of glue-filled passages of appreciable length between thevalve and its respective dispensing ports.

SUMMARY OF THE INVENTION pact pressurefactuated valve for each of itsdispensing ports.

The valve for each port opens when the applicator is supplied with glueat normal dispensing pressureand closes when the supply of glue to theapplicator is shut off. The flow-operating means of each valve arelocated directly adjacent its corresponding dispensingport. Accordingly,no appreciable glue drainage, if any, occurs through the dispensingports when the main dispensing valve is closed.

The preferred pressure-actuated valve for each dispensing port is anelastic valve sleeve surrounding the communicating passage between theport and the applicator inlet. The exit or downstream end of this valvesleeve is located directly adjacent its respective dispensing port andnormally assumes a constricted configuration in which the passagethrough the valve is constricted to block flow to the port. When glue issupplied to the applicator at normal dispensing pressure, the pressureof the glue acts internally of the valve sleeve to expand or open itsconstricted end and thereby permits the glue to pass through the sleevethrough the dispensing port. The applicator is uniquely constructed tofacilitate cleaning and replacement of the individual dispensing portvalves, when necessary.

As noted earlier while the invention is primarily concerned with glueapplicators, it may be utilized for dispensing other liquids.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is an elevational view of acarton forming and sealing machine embodying glue applicators accordingto the invention;

FIG. 2 is an enlarged view of one of the applicators looking in thedirection of the arrows on line 2-2 in FIG. 1;

FIG. 3 is an end view of the dispenser taken on line 3-3 in FIG. 2;

FIG. 4 is an enlarged section through the applicator taken on line 4-4in FIG. 2;

FIG. 5 is a further enlarged perspective view of one of the individualdispensing port valves embodied in the applicator; and

FIG. 6 is an end view of the port valve.

DESCRIPTION OF THE PREFERRED EMBODIMENT The drawings illustrate animproved liquid dispenser I0 according to the invention which, in thisinstance, is a glue applicator for a carton-forming machine 12. Theapplicator has a 14 which is split, along a parting plane P, into twomating sections 14a, 14b. These body sections are joined by bolts 15.Extending through the body is a passage 16 defining an inlet I8 and amanifold 20 within the rear body section 14a and a number of branchpassages 22 within the front body section 14b terminating in dispensingports 24. The inlet 18 and branch passages 22 extend normal to and openthrough the parting faces of their respective body sections 14a, 14b.The manifold 20 intersects the inlet at right angles and opens laterallythrough the parting face of the rear body section. The dispensingports24 extend at oblique angles from the forward ends of the branch passages22 and open through a rounded exterior work-engaging surface 26 on thefrom body section 14b.

Contained with each branch passage 22 is a pressure-actuated valve 28for the adjacent dispensing port 24. Each illustrated port valve 28 isan elastic valve sleeve surrounding the respective branch passage.Downstream or exit end 30 of the valve sleeve assumes a normalconstricted or flattened configuration, shown in FIG. 5, when flow ofglue to the applicator inlet 18 is cut off. In this flattenedconfiguration, the valve sleeve constricts the passage through thesleeve to block glue flow to the adjacent dispensing port 24. It will beobserved that the exit end of each valve sleeve is located immediatelyadjacent its dispensing port, and the port is a small-diameter vein orpassage. Accordingly, virtually no drainage through the port occurs whenglue flow to the applicatoris cut ofi. When glue is supplied totheapplicator inlet at normal dispensing pressure, the pressure of theglue acts internally of each valve sleeve 28 to expand or openits'constricted exit end, as shown in FIG. 6, to permit glue flow to theadjacent dispensing port.

Surrounding the upstream or inlet end of each dispensing port valvesleeve 28 is a flange 32. The inlet end of each branch passage 22 iscounterbored to receive this flange. Accordingly, when the applicatorbody sections 14a, 14b are as sembled, the valve sleeves are firmlyretained in position within the branch passages of the applicator. Thevalve sleeves may be easily removed for cleaning or replacement, whennecessary, by separating the body sections.

The present glue applicator may be installed in a variety ofcarton-forming machines and in any position in such machines. In themachine of FIG. 1, the applicators are installed in inclined attitudes,for example. The applicators are placed so that their dispensing ports24 open toward the carton surfaces to be bonded when the cartons travelpast the applicators. The several applicators are connected to apressurized glue supply (not shown) through conduits 34 and a main gluesupply valve (not shown). This supply valve is actuated by each cartonapproaching the gluing station. When thus actuated, the supply valveopens to feed glue at normal dispensing pressure through theapplicators. The several dispensing port valves 28 in each applicatorare open by glue pressure to permit glue flow from the inlet to theapplicator dispensing ports 24. When the supply valve closes to shut offglue flow to the applicators, the port valves reclose, i.e., return totheir normal constricted configurations, to block glue drainage to thedispensing ports.

What is claimed as new in support of Letters Patent is:

1. A dripless glue dispenser for applying liquid glue to a workpiececomprising:

a body having a surface for contacting said workpiece, and a gluepassage providing a valve chamber, a glue inlet opening to one end ofsaid chamber for receiving liquid glue under pressure, and a dispensingport extending from the other end of said chamber through said bodysurface for dispensing said glue onto said workpiece, and

a resilient valve sleeve within said valve chamber sealed at one end tosaid body at said one chamber end and having a tip at the other chamberend which assumes a constricted configuration to cut off glue flow tosaid dispensing port when the glue flow to said inlet is cut off andopens to pass glue to said port when said inlet receives glue underpressure.

2. A glue dispenser according to claim 1 wherein: 7

said body is split into mating body sections in a parting planetransverse to and intersecting said one chamber end,

means joining said body sections, and

said valve sleeve has a flange about said one sleeve end which isclamped between said body sections to seal said valve sleeve to saidbody.

3. A dripless glue dispenser for applying liquid glue to a workpiececomprising:

an elongated body having a longitudinal surface for contacting saidworkpiece and glue passage means providing a number of valve chambersspaced along said body, a manifold extending along said body and openingto one end of said chambers, a glue inlet opening to said manifold forreceiving glue under pressure, and dispensing ports extending from theopposite ends of said chambers through said body surface at positionsspaced therealong for dispensing glue to said workpiece, and

a resilient valve sleeve within each valve chamber sealed at one end tosaid body at said one end of the respective chamber and having a tip atthe other chamber end which assumes a constricted configuration to cutoff glue flow to the respective port when the glue flow to said inlet iscut off and opens to pass glue to the respective port when said inletreceives glue under pressure.

4. A glue dispenser according to claim 3 wherein:

said body is split into mating sections in a parting plane transverse toand intersecting said one end of said chambers,

means joinin said body sections, and each valve s eeve has a flangeabout its one end which is

1. A dripless glue dispenser for applying liquid glue to a workpiececomprising: a body having a surface for contacting said workpiece, and aglue passage providing a valve chamber, a glue inlet opening to one endof said chamber for receiving liquid glue under pressure, and adispensing port extending from the other end of said chamber throughsaid body surface for dispensing said glue onto said workpiece, and aresilient valve sleeve within said valve chamber sealed at one end tosaid body at said one chamber end and having a tip at the other chamberend which assumes a constricted configuration to cut off glue flow tosaid dispensing port when the glue flow to said inlet is cut off andopens to pass glue to said port when said inlet receives glue underpressure.
 2. A glue dispenser according to claim 1 wherein: said body issplit into mating body sections in a parting plane transverse to andintersecting said one chamber end, means joining said body sections, andsaid valve sleeve has a flange about said one sleeve end which isclamped between said body sections to seal said valve sleeve to saidbody.
 3. A dripless glue dispenser for applying liquid glue to aworkpiece comprising: an elongate body having a longitudinal surface forcontacting saId workpiece and glue passage means providing a number ofvalve chambers spaced along said body, a manifold extending along saidbody and opening to one end of said chambers, a glue inlet opening tosaid manifold for receiving glue under pressure, and dispensing portsextending from the opposite ends of said chambers through said bodysurface at positions spaced therealong for dispensing glue to saidworkpiece, and a resilient valve sleeve within each valve chamber sealedat one end to said body at said one end of the respective chamber andhaving a tip at the other chamber end which assumes a constrictedconfiguration to cut off glue flow to the respective port when the glueflow to said inlet is cut off and opens to pass glue to the respectiveport when said inlet receives glue under pressure.
 4. A glue dispenseraccording to claim 3 wherein: said body is split into mating sections ina parting plane transverse to and intersecting said one end of saidchambers, means joining said body sections, and each valve sleeve has aflange about its one end which is clamped between said body sections toseal the respective sleeve to said body.